Modelling of a piezoceramic patch actuator for velocity feedback control

This paper discusses the modelling of a thin panel with a velocity feedback control unit, which is formed by a piezoceramic patch actuator and, at its centre, an ideal point velocity sensor. The model has been used to predict the open loop sensor-actuator frequency response function in a wide frequency band, up to 80 kHz, so that the stability of the feedback control loop can be properly assessed using the Nyquist criterion. In particular the inertia and stiffness effects produced by the actuator on the frequency response function have been analysed. Simulation results have highlighted that the inertia effect produces amplitude reduction and phase lag at higher frequencies. The stiffness effect reduces the amplitude at low frequencies, decreases the phase lag at higher frequencies and produces an amplitude modulation effect at higher frequencies. Comparison with a measured frequency response function indicates that the proposed model has captured the principal characteristics of the sensor-actuator open-loop frequency response function up to 80 kHz.